The goal of this Phase II project is to demonstrate the prototype of a fully implantable rotary ventricular assist device (VAD). This pump utilizes the advanced three-dimensional magnetic suspension for the rotor demonstrated during Phase I. This bearing system requires neither position sensors nor active feedback electronics, resulting in the simplest 3-0 magnetic bearing available for blood pumps. The bearing coils form part of a tuned inductance-capacitance-resistance (LCR) circuit. A sine wave generator powers the coil. Motion of the rotor varies the inductance and therefore tuning of the circuit such that changes in electrical current flow always occur to oppose the direction of motion. Control of the rotor position is inherent in the bearing construction and Eamshaw?s Law is satisfied. Phase I demonstrated that this bearing construct can be dynamically stable, low in power consumption, and adequately stiff to handle externally applied shock and vibration loads. During Phase II, the program will advance to design and develop a prototype implantable rotary VAD and electronics package and perform in-vivo tests and in-vitro endurance tests. Successful completion will lead directly to a Phase Ill effort and ultimately FDA approval for clinical trials. PROPOSED COMMERCIAL APPLICATION: Heart disease remains the leading cause of death and disability in the United States. Of the 600,000 Americans who die each year due to heart-related problems, about 30,000 to 60,000 could probably be saved with heart transplants. However, the shortage of donor hearts precludes this, and has stimulated the development of many mechanical heart assist and replacement devices. Should mechanical assist pumps prove sufficiently safe and reliable, the potential use to improve the quality of life for cardiac-impaired patients dramatically expands the market.